Think Again About That Block: Commentary on an article by Surena Namdari, MD, MSc, et al.
As an alternative, bupivacaine liposome injectable suspension is a local analgesic that is approved by the U.S. Food and Drug Administration (FDA) for administration into the surgical site. Although there has been some early literature detailing its use in hip and knee joint replacement, this current study, “Randomized Controlled Trial of Interscalene Block Compared with Injectable Liposomal Bupivacaine in Shoulder Arthroplasty,” by Namdari et al. details the results from a prospective, non-blinded, randomized controlled trial with clearly defined end points of in-hospital pain scores and postoperative analgesic consumption within the first 24 hours for specific diagnoses relevant to shoulder arthroplasty while excluding patients with major comorbidities. An equivalent number of patients were randomized to either the interscalene brachial plexus blockade group or the bupivacaine liposome injection group (78 patients each), with the primary outcome variable being morphine equivalent units. Namdari et al. found that patients treated with bupivacaine liposome injectable suspension required an equivalent amount of postoperative narcotics and greater intraoperative narcotics compared with patients treated with interscalene brachial plexus blockade. Moreover, although interscalene brachial plexus blockade provided improved pain scores for the first 8 hours after the surgical procedure, pain scores were worse at 24 hours.
Although the authors did not explore and compare other methods of soft-tissue infiltration, such as non-liposomal injectable bupivacaine or alternative infiltration cocktails, this study does provide clinically relevant data that are timely and relevant to the readership of JBJS. It should be noted that some might consider this technique laborious as intraoperative infiltration of 20 mL of bupivacaine liposome injectable suspension diluted in 20 mL of saline solution in 0.5-mL increments requires that 80 injections are given to deliver the 40 mL into and around the shoulder. Also, although the optimal postoperative pain regimen for shoulder arthroplasty and the cost-effectiveness of analgesic techniques require further investigation, the results from this study actually can impact day-to-day management of patients undergoing shoulder arthroplasty. In my own early clinical experience with this technique, there have been a few patients who had some early increase in narcotic use in the immediate postoperative period, but this was of no clinical importance, especially in light of the satisfaction from patients being immediately able to use the involved extremity. Moreover, both patients and orthopaedic nurses who take care of these patients in the immediate postoperative time period can readily appreciate the lack of rebound pain and the ensuing reduced time in the hospital. As such, orthopaedic surgeons who perform shoulder arthroplasty should seriously consider the use of the local delivery of bupivacaine liposome injectable suspension as a viable alternative to regional interscalene brachial plexus blockade for managing postoperative pain.